SolarEdge - Combine everything on the roof; one home run coming down?

[Rocksteady2R]

So, my guys stumped me with a question and i want to talk through the issue here, although writing this has made me understand most of it by talking it out.

a) SE has 5250W max per string, but you can combine strings in parallel, which is just fine.
a.1) this means that I design them as 2 strings of 15, going into one string input, and another combo of 2 strings of 15 into the second input.
a.2) I'd thought this went into electrically separate inputs in the inverter)

b) yesterday an installer asks me another question, and shows me a pic of the SE inputs, and I see that both of those inputs are actually on the same terminal block and are combined in parallel directly at the input!

As I write this, it becomes obvious to me, but please - confirm this for me still - it's simply that everything is getting equalized at the panel level and, quite specifically, there are no inverter-interior gains/modulations made to the circuit, because everything is modulated at the optimizer. This is all a no-brainer now that I'm writing it out.

So, it sounds like there is nothing wrong with combining everything on the roof, and running only one set of wires down to the inverter. Maybe a spec on that input block regarding maximum wire size, which I'll look into directly after this, but nothing else. I think we've just been wasting wire for a while now.

Is there anything I am missing here?

[solarix]

Could you be a bit more complete with what you have?
I'm guessing you have 60 panels of unknown size? That's too big for one inverter (single phase).
Anyway, yes - SolarEdge inverters just parallel whatever strings you have into its one and only input.
You can parallel them up on the roof if you want as they are self protecting and don't need fuses.
However, it usually isn't much trouble or expense to bring all the strings to the inverter to make working with them easier and in the future if you have to troubleshoot the strings, you're not doing it on the roof.
If you do have 60 panels, you could do it as three strings of 20 as up to 25 are allowed (assuming that is not too much amps)
Also, one of the beauties of the SE system is the strings don't even have to be the same size or even the same panels.

[sensij]

You can parallel them up on the roof if you want as they are self protecting and don't need fuses.

Huh? More than two strings require fuse protection.

OP, if you aren't combining them on the roof, where do you put the fuses now?

As for the decision to combine or not, it really just comes down to what is the most economical wiring for your installation. The rating for each string is 15 A. I think some have found that with three strings, running it as one 15 A circuit and one combined 30 A circuit tends to be less expensive than combining all three into one 45 A circuit.

Likewise, with four strings, you would have the following choices:
4 x 15 A circuits
2 x 15 A circuits + 1 x 30 A circuit
2 x 30 A circuits
1 x 15 A circuit + 1 x 45 A circuit
1 x 60 A circuit

Again, each of the individual strings would need to be fused where they get combined.

See SolarEdge's white paper on code compliance for more details.